Rz=6400e+3;
H=19100e+3;
R=Rz+H;
T=12*3600;
dT=T/1000;
t=0:dT:T;
fi=(t/T)*2*pi;
x=R*cos(fi);
y=R*sin(fi);
x(1)=R;
y(1)=0;
Vx=0:dT:T;
Vy=0:dT:T;
V=0:dT:T;
for k=2:length(x)
Vx(k)=(x(k)-x(k-1))/dT;
Vy(k)=(y(k)-y(k-1))/dT;
V(k)=sqrt(Vx(k)^2+Vy(k)^2);
end
for k=1:length(x)
end

